New Insights about Pulmonary Epithelioid Hemangioendothelioma: Review of the Literature and Two Case Reports

Figure 4

Histopathologic findings of hemangioendothelioma. (a) Low magnification of the specimen obtained from pulmonary wedge resection reveals a subpleural nodule that extends to adjacent alveoli, with vascular proliferation in the peripheral zone and areas of recent and old hemorrhage. (b) Neoplastic nodule showing tumor cells with an eosinophilic stroma at the periphery. The lesion contains blood filled spaces and respiratory epithelium “trapped” within the lesion is also shown. (c) Higher magnification of the tumor reveals vacuolation of some of the tumor cells, representing primitive angiogenesis. One of these epithelioid cells can be observed with intracytoplasmic lumen and an erythrocyte inside, indicating their vascular nature. (d) Immunostaining for CD34 revealed positivity of the neoplastic cells (brown colour), confirming the endothelial lineage of the tumor.

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